How to build Quadplane Hybrid Drone

This Instructable shows how I built a VTOL (Vertical Take-off and Landing) hybrid drone, aka “Quadplane”, starting with a very basic fixed-wing radio control aircraft kit and customizing it with off-the-shelf quadcopter components. The end result is a very capable multi-purpose drone, ideally suited to a range of technical applications. The hybrid or “Quadplane” concept combines the best of both worlds: Duration,speed and range of a fixed wing aircraft with the vertical flight aspects of a rotary wing aircraft. A typical quadcopter can only fly for around 15 mins and will struggle to cover more than 10Km in a single flight, whereas this quadplane can fly for nearly an hour and cover around 50Km. If a runway is available to use for launch and landing, then the rotary wing components can be removed in a few minutes for fixed-wing only flight. The reduced weight in this form gives around 80mins flight duration and 70Km range.

The drone is dual purpose in the application sense too, because it can be fitted with two sensor types, depending on the task required:

1. Stabilized video for applications in conservation, security, Search & Rescue, surveillance, etc.(see first demo video).

2. High resolution hard-mounted stills camera for photogrammetry, terrain modelling, crop monitoring in agriculture, etc. (the second video shows a typical photogrammetry/3D model application).

The aircraft I chose as the basis for this concept is called a Quanum Observer, which is available as a kit from Hobbyking (it is also sold by other retailers under the name of Volantex Ranger-Ex). This Instructable is not intended to deal with the basic steps required to build the kit into a “standard” RC model – those steps are fairly straightforward and covered in the manufacturer’s instruction manual. Rather, this Instructable covers the mods required to convert the fixed wing aircraft into a hybrid quadplane, capable of autonomous flight and able to carry sensors required for technical tasks as mentioned above.

The wingspan of the aircraft is around 2m and the quadcopter frame is 1m (measured diagonal). All up weight in it’s quadplane form,including batteries and camera, is around 4.8Kg. By removing the quadcopter components (ie. flying it as fixed wing only aircraft) the weight comes down to 3.7Kg, but that obviously requires a landing strip.

Here are the main components of the build, with links to the respective suppliers/manufacturers:

Volantex Ranger-Ex: http://www.banggood.com/New-Version-Volantex-Range…

Futaba 14SG radio control set: http://www.futabarc.com/systems/futk9410-14sg/

Turnigy SK3 3542 1000KV: http://www.hobbyking.co.uk/hobbyking/store/__18163…

Hobbywing 60A ESC: http://www.myrcmart.com/hobbywing-platinum-60a-v4-…

T-Motor MT4006 740KV (x4): http://www.rctigermotor.com/html/2013/Professional…

T-Motor Air 40A ESC (x4): http://www.rctigermotor.com/html/2014/esc_1223/285…

T-Motor carbon props 14 x 4.8 (x4): http://www.rctigermotor.com/html/2013/prop_0904/32…

4S 5,200mAh lipo (x2): http://www.hobbyking.co.uk/hobbyking/store/__56840…

Pixhawk flight controller: https://store.3dr.com/products/3dr-pixhawk

Carbon Fibre Square Box Section 8mm (7mm) – 1m Length (x2): http://www.easycomposites.co.uk/#!/cured-carbon-fi…

Carbon sheet at motor mount: Prepreg Carbon Fibre Flat Sheet 0.5mm: http://www.easycomposites.co.uk/#!/cured-carbon-fi…